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Obsidian, Opal

Obsidian

Obsidian is naturally occurring volcanic glass. It is formed when felsic lava extruded from a volcano cools without crystal growth. It's beautiful spectralite qualities give a lustre similar to Tiger's eye. In some stones, the inclusion of white crystals of cristobalite produce a blotchy pattern, known as snowflake obsidian. Iron and magnesium give the obsidian a dark-green, brown or black color. Obsidian may contain patterns of gas bubbles remaining from the lava flow, aligned along layers created as the molten rock was flowing before being cooled. These bubbles can produce interesting effects such as a golden or rainbow sheen. In addition to its use as a gemstone, obsidian has been used in cardiac surgery, since well-crafted obsidian blades have a cutting edge many times sharper than high-quality steel surgical scalpels, with the edge of the blade being only about 3 nanometers wide. Even the sharpest metal knife has a jagged, irregular blade when viewed under magnification. When examined under an electron microscope an obsidian blade is still smooth and even. It is also known as "dragon glass" and the only proven method of killing white walkers. Obsidian is found in many locations that have seen volcanic activity, including Ecuador, Japan, Italy, Iceland, Indonesia, Mexico and the USA.

Opals

More than any other gem, each opal is unique. Its name is derived from the Sanskrit word for 'stone'. Opal is considered to be the national gemstone for Australia, owing to the fact that Australia produces roughly 97% of the world's entire supply of opal gemstones. Opal is famed for its ability to diffract light. Precious opal is known for its remarkable ability to diffract light, which results in rainbow-like colors that change with the angle of observation - known as 'play of color'. Fire opal can sometimes exhibit slight color play, but it is better known for its vivid body color. Opals are delicate gemstones. Their most significant weakness has to do with their water content. If an opal is allowed to dry, it will crack and fade. If you live in a very dry climate, or keep them in a dehumidified room, some precautions are necessary. Keeping them in a tight plastic bag, with a damp piece of cotton or fabric will prevent dehydration. Because of their water content, opals are also highly sensitive to sudden changes in temperature.

We have a stunning range of opals in our Edinburgh silver shop. Boulder opals from Australia set in sterling silver hand, chosen by Uta and made by skilled craftsmen in fair working conditions. Rough and polished Fire opals from Ethiopia as earrings, finger rings, necklaces, beaded and set, and pendants, Peruvian Pink opals from South America in various settings.